The present invention relates to norbornanecarboxyimide having silicon functional groups, and methods for making and modifying such materials. In addition, the present invention relates to use of such silicon containing norbornanecarboxyimide to make silanol terminated polydiorganosiloxanepolyimide block polymers and room temperature vulcanizable compositions (RTV's) resulting therefrom.
Prior to the present invention, room temperature vulcanizable silanol terminated polydiorganosiloxanes, for example, silanol terminated polydimethylsiloxanes were available in either one-package or two-package systems based on the nature of the moisture sensitive cross-linking agents utilized in the composition. A typical one-package system is based on the use of methyltriacetoxysilane and a silanol terminated polydimethylsiloxane as shown by Ceyzeriat, U.S. Pat. No. 3,133,891. A two-package system as shown by Nitzsche et al., U.S. Pat. No. 3,065,194 requires the blending of silanol terminated polydimethylsiloxane with a curing catalyst, such as ethyl orthosilicate in combination with dibutyltindilaurate. The two-package system requires mixing of the curing catalyst with the silanol terminated polydimethylsiloxane prior to use.
The above described one-package and two-package room temperature vulcanizable compositions generally require the use of reinforcing filler, for example, a silica filler in amounts of from 5-300 parts, per 100 parts of silicone polymer, if improved tensile strength in the resulting cured silicone is desired. Another procedure available to improve the toughness of cured silicone polymers in the introduction of silarylenesiloxy units into the polymer chain to produce a copolymer consisting essentially of diorganosiloxy units chemically combined with silarylenesiloxy units. Although these procedures substantially enhance the modulus (psi) of the silicone polymer, these procedures are uneconomic or do not achieve the degree of physical properties desired in the end product.
As taught in my copending application RD-15535, silicon hydride terminated polyimide having the formula, ##STR1## can be used to prepare silanol terminated polydiorganosiloxane polyimide copolymers useful for making high strength RTV compositions, where R is a divalent radical selected from the class consisting of (a) aromatic hydrocarbon radicals having from 6-20 carbon atoms and halogenated aromatic hydrocarbon radicals having from 6-20 carbon atoms, (b) alkylene radicals having from 2-20 carbon atoms and cycloalkylene radicals having from 2-20 carbon atoms, (c) C.sub.(2-8) alkylene terminated polydiorganosiloxane, and (d) radicals included by the general formula, ##STR2## Q' is a member selected from the class consisting of ##STR3## x is a whole number from 1 to 5 inclusive, Q is a tetravalent radical selected from ##STR4## where D is a member selected from ##STR5## and R.sup.8 is a divalent radical selected from ##STR6## and divalent organic radicals of the general formula, ##STR7## X is a member selected from the class consisting of divalent radicals of the formula, ##STR8## y is an integer from 1 to 5, R.sup.1 -R.sup.6 are selected from hydrogen and C.sub.(1-8) alkyl radicals, R.sup.7 is the same or different C.sub.(C1-13) monovalent hydrocarbon radical and substituted C.sub.(1-13) monovalent hydrocarbon radical, -R.sup.9 is selected from H or R.sup.7 Y is a divalent radical selected from --O-- and --C(R.sup.1).sub.2 --, n is an integer equal to 0-200 inclusive, and r and p are whole numbers equal to 0 or 1.
The present invention is based on my discovery that high strength silicon-polyimide copolymer products also can be made by effecting the cure of room temperature or low temperature condensation vulcanizable silanol terminated polydiorganosiloxane-polyimide copolymers resulting from the reaction of silanol terminated polydiorganosiloxane of the formula ##STR9## with silicon functionalized norbornane carboxyimide referred to hereinafter as "silicon-norbornanebisimide" of the formula ##STR10## where R-R.sup.7 are as previously defined, Z is selected from C.sub.(1-8) alkoxy, acyloxy, halogen and amine, and R.sup.9, R.sup.10 and R.sup.11 are selected from Z and R.sup.7 and n is an integer equal to 1-2000 inclusive.
The silanol terminated polydiorganosiloxane-polyimide copolymers which can be made by using the above silicon-norbornane imides of formula (2) comprise by weight from 1 to 99% of polyimide blocks of the formula, ##STR11## chemically combined with from 99% to 1% of polydiorganosiloxane blocks of the formula, ##STR12## where R-R.sup.7, Y, Q, n and m are as previously defined.